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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 13:14:23 +0000
commit73df946d56c74384511a194dd01dbe099584fd1a (patch)
treefd0bcea490dd81327ddfbb31e215439672c9a068 /src/path/match.go
parentInitial commit. (diff)
downloadgolang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.tar.xz
golang-1.16-73df946d56c74384511a194dd01dbe099584fd1a.zip
Adding upstream version 1.16.10.upstream/1.16.10upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/path/match.go')
-rw-r--r--src/path/match.go231
1 files changed, 231 insertions, 0 deletions
diff --git a/src/path/match.go b/src/path/match.go
new file mode 100644
index 0000000..918624c
--- /dev/null
+++ b/src/path/match.go
@@ -0,0 +1,231 @@
+// Copyright 2010 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package path
+
+import (
+ "errors"
+ "internal/bytealg"
+ "unicode/utf8"
+)
+
+// ErrBadPattern indicates a pattern was malformed.
+var ErrBadPattern = errors.New("syntax error in pattern")
+
+// Match reports whether name matches the shell pattern.
+// The pattern syntax is:
+//
+// pattern:
+// { term }
+// term:
+// '*' matches any sequence of non-/ characters
+// '?' matches any single non-/ character
+// '[' [ '^' ] { character-range } ']'
+// character class (must be non-empty)
+// c matches character c (c != '*', '?', '\\', '[')
+// '\\' c matches character c
+//
+// character-range:
+// c matches character c (c != '\\', '-', ']')
+// '\\' c matches character c
+// lo '-' hi matches character c for lo <= c <= hi
+//
+// Match requires pattern to match all of name, not just a substring.
+// The only possible returned error is ErrBadPattern, when pattern
+// is malformed.
+//
+func Match(pattern, name string) (matched bool, err error) {
+Pattern:
+ for len(pattern) > 0 {
+ var star bool
+ var chunk string
+ star, chunk, pattern = scanChunk(pattern)
+ if star && chunk == "" {
+ // Trailing * matches rest of string unless it has a /.
+ return bytealg.IndexByteString(name, '/') < 0, nil
+ }
+ // Look for match at current position.
+ t, ok, err := matchChunk(chunk, name)
+ // if we're the last chunk, make sure we've exhausted the name
+ // otherwise we'll give a false result even if we could still match
+ // using the star
+ if ok && (len(t) == 0 || len(pattern) > 0) {
+ name = t
+ continue
+ }
+ if err != nil {
+ return false, err
+ }
+ if star {
+ // Look for match skipping i+1 bytes.
+ // Cannot skip /.
+ for i := 0; i < len(name) && name[i] != '/'; i++ {
+ t, ok, err := matchChunk(chunk, name[i+1:])
+ if ok {
+ // if we're the last chunk, make sure we exhausted the name
+ if len(pattern) == 0 && len(t) > 0 {
+ continue
+ }
+ name = t
+ continue Pattern
+ }
+ if err != nil {
+ return false, err
+ }
+ }
+ }
+ // Before returning false with no error,
+ // check that the remainder of the pattern is syntactically valid.
+ for len(pattern) > 0 {
+ _, chunk, pattern = scanChunk(pattern)
+ if _, _, err := matchChunk(chunk, ""); err != nil {
+ return false, err
+ }
+ }
+ return false, nil
+ }
+ return len(name) == 0, nil
+}
+
+// scanChunk gets the next segment of pattern, which is a non-star string
+// possibly preceded by a star.
+func scanChunk(pattern string) (star bool, chunk, rest string) {
+ for len(pattern) > 0 && pattern[0] == '*' {
+ pattern = pattern[1:]
+ star = true
+ }
+ inrange := false
+ var i int
+Scan:
+ for i = 0; i < len(pattern); i++ {
+ switch pattern[i] {
+ case '\\':
+ // error check handled in matchChunk: bad pattern.
+ if i+1 < len(pattern) {
+ i++
+ }
+ case '[':
+ inrange = true
+ case ']':
+ inrange = false
+ case '*':
+ if !inrange {
+ break Scan
+ }
+ }
+ }
+ return star, pattern[0:i], pattern[i:]
+}
+
+// matchChunk checks whether chunk matches the beginning of s.
+// If so, it returns the remainder of s (after the match).
+// Chunk is all single-character operators: literals, char classes, and ?.
+func matchChunk(chunk, s string) (rest string, ok bool, err error) {
+ // failed records whether the match has failed.
+ // After the match fails, the loop continues on processing chunk,
+ // checking that the pattern is well-formed but no longer reading s.
+ failed := false
+ for len(chunk) > 0 {
+ if !failed && len(s) == 0 {
+ failed = true
+ }
+ switch chunk[0] {
+ case '[':
+ // character class
+ var r rune
+ if !failed {
+ var n int
+ r, n = utf8.DecodeRuneInString(s)
+ s = s[n:]
+ }
+ chunk = chunk[1:]
+ // possibly negated
+ negated := false
+ if len(chunk) > 0 && chunk[0] == '^' {
+ negated = true
+ chunk = chunk[1:]
+ }
+ // parse all ranges
+ match := false
+ nrange := 0
+ for {
+ if len(chunk) > 0 && chunk[0] == ']' && nrange > 0 {
+ chunk = chunk[1:]
+ break
+ }
+ var lo, hi rune
+ if lo, chunk, err = getEsc(chunk); err != nil {
+ return "", false, err
+ }
+ hi = lo
+ if chunk[0] == '-' {
+ if hi, chunk, err = getEsc(chunk[1:]); err != nil {
+ return "", false, err
+ }
+ }
+ if lo <= r && r <= hi {
+ match = true
+ }
+ nrange++
+ }
+ if match == negated {
+ failed = true
+ }
+
+ case '?':
+ if !failed {
+ if s[0] == '/' {
+ failed = true
+ }
+ _, n := utf8.DecodeRuneInString(s)
+ s = s[n:]
+ }
+ chunk = chunk[1:]
+
+ case '\\':
+ chunk = chunk[1:]
+ if len(chunk) == 0 {
+ return "", false, ErrBadPattern
+ }
+ fallthrough
+
+ default:
+ if !failed {
+ if chunk[0] != s[0] {
+ failed = true
+ }
+ s = s[1:]
+ }
+ chunk = chunk[1:]
+ }
+ }
+ if failed {
+ return "", false, nil
+ }
+ return s, true, nil
+}
+
+// getEsc gets a possibly-escaped character from chunk, for a character class.
+func getEsc(chunk string) (r rune, nchunk string, err error) {
+ if len(chunk) == 0 || chunk[0] == '-' || chunk[0] == ']' {
+ err = ErrBadPattern
+ return
+ }
+ if chunk[0] == '\\' {
+ chunk = chunk[1:]
+ if len(chunk) == 0 {
+ err = ErrBadPattern
+ return
+ }
+ }
+ r, n := utf8.DecodeRuneInString(chunk)
+ if r == utf8.RuneError && n == 1 {
+ err = ErrBadPattern
+ }
+ nchunk = chunk[n:]
+ if len(nchunk) == 0 {
+ err = ErrBadPattern
+ }
+ return
+}